2. Two hours before grilling, prepare marinade. Place chicken breasts in a 1-gallon, resealable plastic bag. In a small bowl, stir together rum, onion, lime juice, and vegetable oil. Pour marinade over chicken, push out air, seal the bag, and refrigerate, turning occasionally, for 2 hours.

3. Fire up the grill:For a charcoal grill: Open the bottom vents. Ignite 6 quarts or 2 1/2 pounds charcoal briquettes or hardwood charcoal. When the coals are hot, set up for a one-level medium-heat fire (so you can hold your hand 5 inches above the cooking rack for only 4 to 5 seconds).For a gas grill: Turn each burner to high and ignite. Cover the grill. When hot, set the burners to medium heat.

4. Remove chicken from marinade, drain, and discard the bag and marinade. Season chicken with salt, and let it sit at room temperature until the grill's ready.

5. On a charcoal grill: Grill chicken, uncovered, 5 to 6 minutes per side, until chicken is no longer pink in the center or until an instant-read thermometer inserted into the center of the thickest part registers 160°F.On a gas grill: Grill chicken, covered, 10 to 12 minutes, turning once halfway through, until chicken is no longer pink in the center or until an instant-read thermometer inserted into the center of the thickest part registers 160°F. Remove chicken from the grill, and serve.

Note: To add authenticity, you could serve a Caribbean hot sauce as a condiment with these chicken breasts. Caribbean hot sauces are generally a fragrant combination of high-heat habanero or scotch bonnet chilies with a touch of mustard. Use them a few drops at a time.